EVALUATION METHOD OF PIPE WEAR FOR DEVELOPMENT OF SEAFLOOR MASSIVE SULFIDES

Abstract

 The evaluation of pipe wear is necessary to design the mining system for development of seafloor massive sulfides. The authors conducted three types of the flow loop wear experiment to obtain the basic data of pipe wear during slurry transport. In these experiments, the characteristics of pipe wear for different inner materials and pipe inclinations were investigated. As a result of the experiments, the wear resistance of SUS304 was shown to be higher than those of plastic and rubber materials, and the wear volume of pipe inclined at 30 degrees was largest in the experiment. Then the influence of solid degradation on the wear rates was also investigated. The authors estimated the wall thickness reduction for the lifting pipe based on the results of the flow loop wear experiments. The estimation results showed that it took 89 days to reduce wall thickness by 1mm for a rigid riser made of SUS304.